Definition of Locrian mode in English:

noun

Thus, much of his analysis derives from his asking participants whether, and how, a specific chord ‘feels’ like a tonic or a subdominant, etc., or whether a guitar riff ‘feels’ in the Locrian mode, etc.

Origin

Late 19th century: Locrian from Greek Locris, a division of ancient Greece, + -ian; named after an ancient Greek mode but not identifiable with it.